The effect of plasticization on the properties of poly(urethaneureas) based on oligoether diols, 2,4-toluenediisocyanate, and aromatic diamines

Abstract

Segmented poly(urethaneureas) (SPUUs) modified with low glass transition temperature chemically inert liquids are of interest due to their controllable properties and potential applications under various environmental conditions. Investigation into the influence of plasticizers on the properties of SPUUs based on oligotetramethyleneoxide diol (polytetramethyleneoxide), oligopropyleneoxide diol (polypropyleneoxide), 2,4toluenediisocyanate, Ethacure-300, and methylene-bis-o-chloroaniline was conducted. Partial crystallization of polytetramethyleneoxide segments was identified during cooling of some SPUU samples plasticized by di-(2-ethylhexyl)sebacate (DEHS) and tributyl phosphate. Polypropyleneoxide segments did not crystallize under the same conditions. A low crystallization temperature for the amorphous component of the polymer matrix in SPUU (À100 C to 103 C) was attained at a molecular mass (M n) of soft segments equal to 2000 g mol À1 and a DEHS concentration equal to 40-45%. A relationship between the mechanical properties of plasticized SPUU, microphase segregation, and dilution of the polymer matrix was found. For the first time, the effect of dilution with plasticizer on the strength of elastomers was considered. The plasticization effect on the mechanical properties of SPUU was investigated in the temperature diapason from 50 C to À70 C. The results of these investigations can be used in various technologies including the design of SPUUs with high elastic properties at temperatures as low as À70 C, typical of extreme conditions of the Arctic climate.

Robust Stretchable Thermoplastic Polyurethanes with Long Soft Segments and Steric Semisymmetric Hard Segments

“…The tensile strength (32.0 MPa) of PTMG 2k -HMDI 2.5 was higher than those of all the reported PTMG-based TPUs, and PTMG 2k -HMDI 2.5 possessed a high elongation at break above 1300% simultaneously (Figure c). ,,,,,− This demonstrates that the robust and stretchable PTMG-based TPU can be prepared by selecting HMDI with BDO as HSs and PTMG with a relatively high molecular weight of 2000 g·mol –1 as SSs without introducing other chemical bonds, such as disulfide bond, transition metal complexation, borate ester, etc.…”

“…(b) Stress–strain curves of three samples of HMDI-based TPUs with different molecular weights of 1000 and 2000 g·mol –1 in PTMG segments. (c) Ashby plot of “tensile strength” and “elongation at break” of PTMG 2k -HMDI 2.5 and other PTMG-based TPUs reported in the literature. ,,,,,− …”

Microstructure and mechanical properties of self-reinforced cross-linked polyurethanes based on oligobutadiene diol

“…Известно большое количество работ, где изучается формирование так называемых мягких и жестких блоков ПУ матрицы и влияние микрофазного разделения на механические свойства образцов ПУ [12][13][14][15][16][17][18][19][20][21]. В частности, исследовано влияние соотношения жестких и мягких блоков, химического состава и надмолекулярной структуры на растяжение полиуретановых эластомеров [12].…”